Tubemaking apparatus



5 Sheets-Sheet l Filed Feb. 4, 1966 r l j E m? INVENTOR.

Mar @feat Aug. l2, 1969 K. Rlr-:D 3,460,445

TUBEMAK ING APPARATUS INVENTOR. 14a, d ,@/u

Aug. l2, 1969 K. RIED l 3,460,445

TUBEMAKING APPARATUS Filed Feb. 4, 1966 5 Sheets-Sheet 3 INVENTOR um,@leg 'SY/wwf. MW

ATTORNEY nited 3,460,445 TUBEMAKING APPARATUS Karl Ried,Sanatorumstrasse, Unterageri, Switzerland Filed Feb. 4, 1966, Ser. No.525,156 Claims priority, application Switzerland, Feb. 4, 1965, 1,536/65 Int. Cl. Ble 1/02; B65d 3/04 U.S. Cl. 93-80 15 `Claims ABSTRACT F THEDISCLOSURE The present invention relates to a tubemaking apparatus. Morespecifically, the invention relates to an apparatus for making tubes byhelically convoluting strips of tape-material. Such apparatus, by virtueof its novel operation and simple construction, will increase the rateof tube production while decreasing the downtime resulting 4inconventional apparatus of this type from Separation of the stripconvolutions and from other causes which will become apparent hereafter.

It is known to construct tubes by helically convoluting one or morestrips of tape-material, and by thereafter suitably securing theconvolutions together. Such tubes find wide use in a variety ofapplications, for instance as a core on which rolls of various paperproducts are wound, such as wrapping paper and paper towelling.

In constructing tubes in this manner it is known to convolute the stripof tape-material, which is treated with an adhesive, about a mandrel andsubsequently to pass the thus formed tube to a pressing means whichserves to press the convolutions of tape-material against one another,so as to cause them to adhere. However, known tubemaking apparatus ofthis type suffers from various drawbacks. For example, the convolutionsof tape-material have a tendency to separate, frequently by slipping inaxial direction of the mandrel, prior to and sometimes even afterreaching the pressing means. This usually requires that production beinterrupted and the convoluting process of the tape-material about themandrel be restarted. It will be understood that, once such slippage ofthe convolutions occurs, it w-ill frequently propagate itself back tothe winding station at which the convolutions are applied onto themandrel. Naturally, if the tapematerial shifts at the point at which itfirst engages the mand-rel, then the next-following convolution cannotproperly be joined to the previous one and a proper tube cannot beproduced.

An additional diiiiculty with known tubemaking machines of this type isthe fact that it is difficult to produce tubes having relatively thickwalls, particularly in view of the fact that in such cases it isnecessary to use several strips of tape-material, each one of which mustbe relatively thick, so that proper positioning and maintaining of theconvolutions becomes even more ditlicult because of the resistance ofthe material.

Taking into account these various problems, it is a general object ofthe present invention to overcome the above-mentioned drawbacks of theprior art.

A more specific object of the present invention is to provide atubemaking apparatus in which relative diste t placement of theconvolutions of the tape-material on the mandrel is prevented.

Yet a further object of the invention is to provide an apparatus of thetype outlined above which will permit the use of tape-material ofrelatively great thickness without increased danger of relativedislocation of the convolutions formed by such tape-material.

In accordance -with one feature of the invention, and in pursuance ofthese objects and others which will become apparent hereafter, I providein a tubemaking apparatus a combination of:

(a) An elongated mandrel for supporting a tube from the inside thereof;

(b) Tube-forming means for forming on said mandrel an axially movingtube consisting of helically convoluted adhesive-coated tape-material;and

(c) A plurality of pressing means spaced in axial direction of saidmandrel and engaging axially spaced portions of said tube forcompressing successive increments of the moving tube.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. l is a top-plan view of an embodiment of the present invention;

FIG. 2 is a View similar to FIG. 1, showing a lsomewhat diiferentembodiment;

FIG. 3 is a schematic showing of a hydraulic drive means for use withthe present invention;

FIG. 4 is a top plan view of the drive means shown in FIG. 3; and

FIG. 5 is an axial end view illustrating another embodiment of theinvention.

Discussing now the drawing in detail, and firstly FIG. l thereof, itwill be seen that there is shown a mandrel 1 about which there moves arotating tube 5 which advarices axially in direction of the arrow 5'.Convoluting of the tape-material about the mandrel l is not shown sincein itself this is Well known in the art. This takes place in the tubeforming means which is indicated in the drawing in FIG. l with acorresponding legend. Tube forming means capable of being utilized forthis purpose is disclosed, for instance, in U.S. Patents 1,693,850 and1,714,541.

Downstream of the tube forming means there is arranged a first pressingmeans comprising a pair of rollers 3, 4 which are respectively disposedon opposite sides of the tube 5, and are shown here to be located in acommon transverse plane. Guided around these rollers 3, `4 is an endlessbelt 2 having two stringers, one of which passes by the tube 5 laterallythereof and substantially transversely of the axial extension of thetube ll whereas the other Stringer is convoluted about the tube. Therollers 3, 4 rotate in direction of the respective associated arrows andconsequently the belt Z travels in the direction indicated by the arrowsprovided thereon.

In the particular embodiment shown in FIG. 1 a second pressing meansidentical with the rst one is arranged spaced from the irst pressingmeans in axial direction ofl the tube 5. The rollers of this secondpressing means are designated with reference numerals 3a, 4a and thebelt is designated with reference numeral 2a.

As the already formed tube 5 leaves the tube-forming means and movesaxially in direction of the arrow 5', the convolutions of tape-materialdo not yet properly adhere to one another. As, now, each successiveincrement of the tube passes the iirst pressing means, the tubeconvolutions are compressed one against the other by the action of thetravelling belt 2 which engages the tube 5 on the exterior thereof.

If the tape-material used for producing the tube is coated with apressure sensitive adhesive, this tirst cornpression would cause bondingof the convolutions to one another. However, although the use of suchpressure-sensitive adhesive is possible, it is not common for theproduction of tubes of this type, for various reasons, one of thesebeing the greater economy of other types of adhesives, particularly thetype which requires a certain period of time for setting. It will beclear, on the other hand, that if an adhesive is used which requiressome time to set and form a reliable bond, that then the belt 2 of thefirst pressing means can do nothing more than press the convolutionsagainst one another so as to establish a -good contact, since theadhesive is not yet set when the respective increment of the tube 5passes beyond the belt 2 in direction of the arrow 5. Thus, there isstill a danger that the convolutions might become dislocated withrespect to one another, thus resulting in a defective tube.

This tendency is counteracted by the positioning of the second pressingmeans whose lbelt 2a engages the tube with one of its stringersdownstream of the point at which the first pressing means engages it. Inaccordance with one feature of the present invention the spacing betweenthe second and iirst pressing means will `be so selected that the timeinterval required for any given increment of the tube to travel from theiirst pressing means to the second pressing means corresponds to theperiod which the adhesive requires for setting, so that the adhesivewill be completely or substantially set by the time the respectiveincrement of the tube reaches the second pressing means. It should beunderstood that the belt 2a of the second pressing means is provided notonly for imparting a iinal compression to the convolutions of the tube5, but also to counteract any forces which might try to separate theconvolutions of the tube downstream of the lirst pressing means, forinstance by axial slippage or by unwinding, and which could thus resultin production of a damaged tube. In fact, the provision of the secondpressing means, by reinforcing the compression of the tube convolutionsWhile maintaining the convolutions against displacement, permits theproduction of a tube of much -greater resistance to bending or breaking.Furthermore, with this arrangement it is possible to use a larger numberof individual strips of tape-material then has been done herebefore, andsuch strips can be of thinner material than is customary, since the twopressing means assure that the convolutions formed by all of thesestrips will be tightly pressed together into a tube having a very goodresistance to breaking and bending.

The danger of convolution slippage is additionally counteracted by thefact that the endless belts: 2 and 2a are so arranged as to exert pullin opposite directions. This may be achieved by rotating the pairs ofrollers 3, 4 and 3a, 4a in opposite directions. If, however, it isdesired to rotate the pairs of rollers in identical directions, thenoppositely directed pull can be achieved by having one of the belts 2,2a extend crosswise of the other.

In the embodiment shown in FIG. 2, which is otherwise largely similar tothat of FIG. 1, the rollers 3 of the first pressing means and 3a of thesecond pressing means are arranged closer together, as seen with respectto the axial extension of the mandrel 1, than the rollers 4, 4a of therespective pressing means. This results in a trapezoidal arrangement ofthe rollers. Also, it will be seen that the not convoluted Stringer ofthe first pressing means, that is of the belt 2, passes laterally of thetube 5 on one side thereof, whereas the not convoluted stringer of thebelt 2a of the second pressing means passes by the tube on adiametrically opposite side thereof. Of course, other arrangements ofthe rollers and belts are possible, and

of these only one possibility will be mentioned here, namely astar-shaped arrangement of the iirst and second pressing means in whichthe same are arranged substantially in a common vertical plane. Thispermits a machine incorporating the present invention to be constructedof shorter axial length than would otherwise be possi-ble. Such anarrangement is shown in FIG. 5 which is believed to require no furtherexplanations, being self-explanatory inasmuch as the various illustratedcomponents are the same as in FIGS. 1 and 2.

Coming now to FIGS. 3 and 4, it will be seen that there is shown thereina drive means suitable for driving the pressing means shown in FIGS. 1and 2. It is preferred that all rollers 3, 4 and 3a, 4a of the rst andsecond pressing means have a common drive. To this end each of therollers 3, 4 and 3a, 4a is provided with a huid-driven motor 10. It isto be noted that the roller 4a is not visible in FIG. 3.

In the arrangement shown in FIG. 3, which is by Way of example only,there is provided a gear pump 6 which is connected by a pressure conduit7 with a feed conduit S communicating with the respective hydraulicmotors 10 `of the rollers 3, 4 and 3a, 4a. A return-flow conduit 9 inthe form of a collecting conduit connectors the uid motors 10 andcommunicates with the gear pump 6, so that iluid fed to the motors 10through the feed conduit 8 is passed into the return-flow conduit 9 andfrom there reaches the gear pump 6 for recirculation. A bypass conduit15 connects the pressure conduit 7 with the return-ilow conduit 9downstream of the gear pump 6, but upstream of the feed conduit 8. Apressure relief valve 5 is provided in the bypass conduit 15 and is soselected that it will open only upon Huid pressure in the pressureconduit 7 exceeding a predetermined maximum. Down stream of the point atwhich the bypass conduit 15 communicates with the pressure conduit 7,but upstream of the feed conduit 8, there is arranged a shutoff valve 11which permits selective opening and closing of the pressure conduit 7and thereby enable selective establishing of communication between thepressure conduit 7 and the feed conduit 8. This shut-oli valve is hereshown as consisting of a rotary gate 13 which engages with its oppositeends arcuate wall portions 14 so that, as the gate is rotated in a sensein which both opposite ends engage the wall portions 14, ow of tiuidthrough the valve 11 is completely stopped, whereas, when the gate isrotated n a sense in which its end portions move away from the wallportions 14, flow of uid through the valve 11 becomes possible, withmaximum ow taking place when the gate 13 extends parallel to thedirection of ilow. It should be understood that shut-olf valves ofdifferent construction are suitable zfor this purpose and that the oneshown and described herein is mentioned by Way of example only.

The operation of the drive will be clear from what has been said before,and from a consideration of the drawing. The gear pump 6, which isdesigned to pump a somewhat greater volume yof fluid than is requiredfor driving the motors 10, feeds the lluid through the pressure conduit7 in the direction of the arrow. It the valve 11 is closed, pressurebuilds up in the pressure conduit 7 to a predetermined level. When thislevel is exceeded, the relief valve 12 opens and permits escape of iluidthrough the bypass conduit 15 and into the return-ow conduit 9. In thereturn-flow conduit 9, the fluid is prevented -from owing in directiontowards the motors 10 by the check valves 15 which are installed in theconduit 9, so that the fluid must necessarily return to the gear pump 6.When the gate 13 of shut-olf valve 11 is slowly opened to an increasingextent, the fluid can pass from the pressure conduit 7 into the feedconduit 8 and from there into the fluid motors 10 which thussimultaneously and gradually are accelerated under full load conditions.

It should be pointed out that various modifications are possible andwill offer themselves readily to those skilled in the art. Suchmodifications are intended to be encompassed in the protection sought.It will also be obvious that the invention is suitable for use withstrips of tape-material of various types, for instance paper, lightcardboard, plastics, metal foil and similar materials.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types of atubemaking apparatus differing from the types described above.

While the invention has been illustrated and described as embodied intubemaking apparatus, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

I claim:

1. In a tubemaking apparatus, the combination of an elongated mandrelfor supporting a tube from the inside thereof; tube-forming means forforming on said mandrel a tube moving axially at a predetermined speedand consisting of helically convoluted tape material coated with anadhesive which is applied in non-set state and requires a setting periodfor establishing a bond; and pressing means spaced in axial direction ofsaid mandrel and engaging axially spaced portions of said tube forcompressing successive increments thereof, said pressing means includinga first and a second endless driven belt each having a Stringer forminga convolution about said tube, said adhesive on any increment of saidtube being in non-set state when such increment passes said first beltand said second belt being spaced from said first belt downstreamthereof by a distance whose traversal by such increment at saidpredetermined speed requires a time interval corresponding to saidsetting period.

2. In a tubemaking apparatus, the combination of an elongated mandrelfor supporting a tube from the inside thereof; tube-forming means forforming on said mandrel a tube moving axially at a predetermined speedand consisting of helically convoluted tape material coated with anadhesive which is applied in non-set state and requires a setting periodfor establishing a bond; and pressing means spaced in axial directionsof said mandrel and engaging axially spaced portions of said tube forcompressing successive increments thereof, said pressing means includinga first and a second endless driven belt each having a Stringer forminga convolution about said tube, the Stringer of one of said belts beingdisposed ou one side of said tube and convoluted about the latter fromsaid one side, and the stringer of the other of said belts beingdisposed on a diametrally opposite side of said tube and convolutedabout the latter from said opposite side.

3. In a tube making apparatus as dened in claim Z, said pressing meansfurther comprising a pair of guide rollers for each of said belts andabout which the respective belt travels, one roller of each pair beinglocated on one side of said tube and the other roller of each pair beinglocated on an opposite side of said tube, the rollers located on saidother side being farther spaced from one another in axial direction ofsaid tube than the rollers located on said one side.

4. An apparatus as defined in claim 3, wherein said rollers are arrangedin a substantially horizontal common plane.

5. A tubemaking apparatus as defined in claim 2, further comprising apair of rollers associated with each of said belts supporting the same;and drive means counected with said rollers for driving the same andthereby said belts, said drive means including a fluid-operated motorfor each of said rollers and a hydraulic system operatively connectedwith the respective motors for driving the same.

6. An apparatus as defined in claim 5, wherein said hydraulic systemcomprises a pump, conduit means containing a fiuid and includingfeed-conduit means connecting said pump with the respective motors forfeeding said fiud thereto, return-flow conduit means connecting saidmotors with said pump for returning said fluid to the latter, by-passconduit means connecting said return-fiow conduit means with saidfeed-conduit means upstream of said motors, and adjustable valve meansarranged in said feed-conduit means upstream of said motors anddownstream of said by-pass conduit means for selectively varying theflow of fiuid to said motors whereby, when said valve means is at leastpartially open, fluid will flow to said motors and drive the samewhereas, when said valve means is closed, fluid will flow through saidby-pass conduit means into said return-flow conduit means.

7. An apparatus as defined in claim 6; and further comprisingpressure-responsive valve means located in said by-pass conduit meansand arranged to open upon the pressure of fluid in said feed-conduitmeans exceeding a predetermined level.

8. An apparatus as defined in claim 7; and further comprising one-wayvalve means arranged in said return-How conduit means upstream of thelocation at which said bypass conduit means communicates with the same,for preventing fiow of fiuid from said by-pass conduit means to saidmotors.

9. In a tubemaking apparatus, the combination of an elongated mandrelfor supporting a tube from the inside thereof; tube-forming means forforming on said mandrel an axially moving tube consisting of helicallyconvoluted adhesive-coated tape material; and a plurality of pressingmeans spaced in axial direction of said mandrel and er1- gaging axiallyspaced portions of said tube compressing successive increments of themoving tube, said pressing means including two endless belts each havinga Stringer forming a convolution about said moving tube, and a pair ofdriven guide rollers for each of said belts about which the respectivebelt travels, said guide rollers of each pair rotating in mutuallyopposite directions and the pairs of guide rollers being so arrangedthat said belts define with one another a trapezoidal outline and exertpull on said tube in mutually opposite directions, said pressing meansbeing arranged to define a star shape with one another and beingsubstantially located in a common vertical plane.

10. In a tubemaking apparatus, tube forming means for forming an axiallymoving unfinished tube which requires for finishing the application ofpressure on its outer surface; and pressing means, including twopressing units spaced in axial direction of said moving unfinished tubeand comprising respective endless driven belts each having a stringerconvoluted about and engaging axially spaced portions of said tube forpressing against successive increments thereof, and means supportingsaid belts, said pressing units being arranged at circumferentiallydifferent angular positions relative to said tube so that the stringersof said endless belts of said pressing units are convoluted about saidtube from different sides of said tube.

11. In a tubemaking apparatus as defined in claim 10, wherein saidendless belts are driven in a sense in which said stringers convolutedabout said tube each travel in the same direction as the other.

12. In a tubemaking apparatus as dened in claim 10, said meanssupporting said belts including two pair of guide rollers, eachassociated with one of said pressing units, about which said beltstravel, and wherein at least one roller of each pair of guide rollers isdriven.

13. In a tubemaking apparatus as defined in claim 10, wherein said tubeforming means is operative for forming said tube from helicallyconvoluted adhesive-coated tape material; and wherein the adhesive withwhich said tape material is coated is of the type which is applied innonset state and which requires a setting period for establishing abond.

14. In a tubemaking apparatus as defined in claim 13, wherein said tubemoves axially at a predetermined speed; the adhesive on any increment ofthe tube being in nonset state when such increment passes the upstreamone of said belts and the downstream one of said belts being spaced fromthe upstream one of said belts by a distance whose traverse by suchincrement at said predetermined speed requires a time intervalcorresponding to said setting period.

15. In a tubemaking apparatus, tube forming means for forming an axiallymoving unfinished tube which requires for finishing the application ofpressure on its outer surface; and pressing means, including twopressing units spaced in axial direction of said moving unfinished tubeand each comprising an endless driven belt each having a stringerconvoluted about and engaging axially spaced portion of said tube forpressing against successive increments thereof, and each pressing unitfurther having a pair of rollers supporting the respective belt, saidrollers of the respective pairs of rotating in mutually oppositedirections and said pairs of rollers being arranged at circumferentiallydifferent angular positions relative to said tube and in such a mannerthat Said belts dene With one another a trapezoidal outline.

References Cited WILLIAM S. LAWSON, Primary Examiner

